* Process all the simulated interrupts - each represented by a bit in \r
* ulPendingInterrupts variable.\r
*/\r
-static void prvProcessPseudoInterrupts( void );\r
+static void prvProcessSimulatedInterrupts( void );\r
+\r
+/*\r
+ * Interrupt handlers used by the kernel itself. These are executed from the\r
+ * simulated interrupt handler thread.\r
+ */\r
+static unsigned long prvProcessDeleteThreadInterrupt( void );\r
+static unsigned long prvProcessYieldInterrupt( void );\r
+static unsigned long prvProcessTickInterrupt( void );\r
\r
/*-----------------------------------------------------------*/\r
\r
\r
} xThreadState;\r
\r
-/* Pseudo interrupts waiting to be processed. This is a bit mask where each\r
+/* Simulated interrupts waiting to be processed. This is a bit mask where each\r
bit represents one interrupt, so a maximum of 32 interrupts can be simulated. */\r
static volatile unsigned long ulPendingInterrupts = 0UL;\r
\r
-/* An event used to inform the pseudo interrupt processing thread (a high \r
+/* An event used to inform the simulated interrupt processing thread (a high \r
priority thread that simulated interrupt processing) that an interrupt is\r
pending. */\r
static void *pvInterruptEvent = NULL;\r
\r
-/* Mutex used to protect all the pseudo interrupt variables that are accessed \r
+/* Mutex used to protect all the simulated interrupt variables that are accessed \r
by multiple threads. */\r
static void *pvInterruptEventMutex = NULL;\r
\r
-/* Events used to manage sequencing. */\r
-static void *pvTickAcknowledgeEvent = NULL;\r
-\r
/* The critical nesting count for the currently executing task. This is \r
initialised to a non-zero value so interrupts do not become enabled during \r
the initialisation phase. As each task has its own critical nesting value \r
ulCriticalNesting will get set to zero when the first task runs. This \r
initialisation is probably not critical in this simulated environment as the\r
-pseudo interrupt handlers do not get created until the FreeRTOS scheduler is \r
+simulated interrupt handlers do not get created until the FreeRTOS scheduler is \r
started anyway. */\r
static unsigned long ulCriticalNesting = 9999UL;\r
\r
/* Handlers for all the simulated software interrupts. The first two positions\r
are used for the Yield and Tick interrupts so are handled slightly differently,\r
all the other interrupts can be user defined. */\r
-static void (*vIsrHandler[ portMAX_INTERRUPTS ])( void ) = { 0 };\r
+static unsigned long (*ulIsrHandler[ portMAX_INTERRUPTS ])( void ) = { 0 };\r
\r
/* Pointer to the TCB of the currently executing task. */\r
extern void *pxCurrentTCB;\r
\r
for(;;)\r
{\r
- /* Wait until the timer expires and we can access the pseudo interrupt \r
+ /* Wait until the timer expires and we can access the simulated interrupt \r
variables. *NOTE* this is not a 'real time' way of generating tick \r
events as the next wake time should be relative to the previous wake \r
time, not the time that Sleep() is called. It is done this way to \r
handler thread. */\r
SetEvent( pvInterruptEvent );\r
\r
- /* Give back the mutex so the pseudo interrupt handler unblocks \r
- and can access the interrupt handler variables. This high priority\r
- task will then loop back round after waiting for the lower priority \r
- pseudo interrupt handler thread to acknowledge the tick. */\r
- SignalObjectAndWait( pvInterruptEventMutex, pvTickAcknowledgeEvent, INFINITE, FALSE );\r
+ /* Give back the mutex so the simulated interrupt handler unblocks \r
+ and can access the interrupt handler variables. */\r
+ ReleaseMutex( pvInterruptEventMutex );\r
}\r
\r
#ifdef __GNUC__\r
long lSuccess = pdPASS;\r
xThreadState *pxThreadState;\r
\r
+ /* Install the interrupt handlers used by the scheduler itself. */\r
+ vPortSetInterruptHandler( portINTERRUPT_YIELD, prvProcessYieldInterrupt );\r
+ vPortSetInterruptHandler( portINTERRUPT_TICK, prvProcessTickInterrupt );\r
+ vPortSetInterruptHandler( portINTERRUPT_DELETE_THREAD, prvProcessDeleteThreadInterrupt );\r
+\r
/* Create the events and mutexes that are used to synchronise all the\r
threads. */\r
pvInterruptEventMutex = CreateMutex( NULL, FALSE, NULL );\r
pvInterruptEvent = CreateEvent( NULL, FALSE, FALSE, NULL );\r
- pvTickAcknowledgeEvent = CreateEvent( NULL, FALSE, FALSE, NULL );\r
\r
- if( ( pvInterruptEventMutex == NULL ) || ( pvInterruptEvent == NULL ) || ( pvTickAcknowledgeEvent == NULL ) )\r
+ if( ( pvInterruptEventMutex == NULL ) || ( pvInterruptEvent == NULL ) )\r
{\r
lSuccess = pdFAIL;\r
}\r
\r
/* Set the priority of this thread such that it is above the priority of \r
the threads that run tasks. This higher priority is required to ensure\r
- pseudo interrupts take priority over tasks. */\r
+ simulated interrupts take priority over tasks. */\r
pvHandle = GetCurrentThread();\r
if( pvHandle == NULL )\r
{\r
\r
if( lSuccess == pdPASS )\r
{\r
- if( SetThreadPriority( pvHandle, THREAD_PRIORITY_BELOW_NORMAL ) == 0 )\r
+ if( SetThreadPriority( pvHandle, THREAD_PRIORITY_NORMAL ) == 0 )\r
{\r
lSuccess = pdFAIL;\r
}\r
if( lSuccess == pdPASS )\r
{\r
/* Start the thread that simulates the timer peripheral to generate\r
- tick interrupts. */\r
+ tick interrupts. The priority is set below that of the simulated \r
+ interrupt handler so the interrupt event mutex is used for the\r
+ handshake / overrun protection. */\r
pvHandle = CreateThread( NULL, 0, prvSimulatedPeripheralTimer, NULL, 0, NULL );\r
if( pvHandle != NULL )\r
{\r
- SetThreadPriority( pvHandle, THREAD_PRIORITY_NORMAL );\r
+ SetThreadPriority( pvHandle, THREAD_PRIORITY_BELOW_NORMAL );\r
SetThreadPriorityBoost( pvHandle, TRUE );\r
SetThreadAffinityMask( pvHandle, 0x01 );\r
}\r
behave as an embedded engineer might expect. */\r
ResumeThread( pxThreadState->pvThread );\r
\r
- /* Handle all pseudo interrupts - including yield requests and \r
+ /* Handle all simulated interrupts - including yield requests and \r
simulated ticks. */\r
- prvProcessPseudoInterrupts();\r
+ prvProcessSimulatedInterrupts();\r
} \r
\r
- /* Would not expect to return from prvProcessPseudoInterrupts(), so should \r
+ /* Would not expect to return from prvProcessSimulatedInterrupts(), so should \r
not get here. */\r
return 0;\r
}\r
/*-----------------------------------------------------------*/\r
\r
-static void prvProcessPseudoInterrupts( void )\r
+static unsigned long prvProcessDeleteThreadInterrupt( void )\r
+{\r
+ return pdTRUE;\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+static unsigned long prvProcessYieldInterrupt( void )\r
+{\r
+ return pdTRUE;\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+static unsigned long prvProcessTickInterrupt( void )\r
{\r
-long lSwitchRequired, lCurrentTaskBeingDeleted;\r
+unsigned long ulSwitchRequired;\r
+\r
+ /* Process the tick itself. */\r
+ vTaskIncrementTick();\r
+ #if( configUSE_PREEMPTION != 0 )\r
+ {\r
+ /* A context switch is only automatically performed from the tick\r
+ interrupt if the pre-emptive scheduler is being used. */\r
+ ulSwitchRequired = pdTRUE;\r
+ }\r
+ #else\r
+ {\r
+ ulSwitchRequired = pdFALSE;\r
+ }\r
+ #endif\r
+\r
+ return ulSwitchRequired;\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+static void prvProcessSimulatedInterrupts( void )\r
+{\r
+unsigned long ulSwitchRequired, i;\r
xThreadState *pxThreadState;\r
void *pvObjectList[ 2 ];\r
-unsigned long i;\r
\r
- /* Going to block on the mutex that ensured exclusive access to the pseudo \r
- interrupt objects, and the event that signals that a pseudo interrupt\r
+ /* Going to block on the mutex that ensured exclusive access to the simulated \r
+ interrupt objects, and the event that signals that a simulated interrupt\r
should be processed. */\r
pvObjectList[ 0 ] = pvInterruptEventMutex;\r
pvObjectList[ 1 ] = pvInterruptEvent;\r
{\r
WaitForMultipleObjects( sizeof( pvObjectList ) / sizeof( void * ), pvObjectList, TRUE, INFINITE );\r
\r
- /* Used to indicate whether the pseudo interrupt processing has\r
+ /* Used to indicate whether the simulated interrupt processing has\r
necessitated a context switch to another task/thread. */\r
- lSwitchRequired = pdFALSE;\r
- lCurrentTaskBeingDeleted = pdFALSE;\r
+ ulSwitchRequired = pdFALSE;\r
\r
/* For each interrupt we are interested in processing, each of which is\r
represented by a bit in the 32bit ulPendingInterrupts variable. */\r
for( i = 0; i < portMAX_INTERRUPTS; i++ )\r
{\r
- /* Is the pseudo interrupt pending? */\r
+ /* Is the simulated interrupt pending? */\r
if( ulPendingInterrupts & ( 1UL << i ) )\r
{\r
- switch( i )\r
+ /* Is a handler installed? */\r
+ if( ulIsrHandler[ i ] != NULL )\r
{\r
- case portINTERRUPT_YIELD:\r
-\r
- lSwitchRequired = pdTRUE;\r
-\r
- /* Clear the interrupt pending bit. */\r
- ulPendingInterrupts &= ~( 1UL << portINTERRUPT_YIELD );\r
- break;\r
-\r
- case portINTERRUPT_TICK:\r
- \r
- /* Process the tick itself. */\r
- vTaskIncrementTick();\r
- #if( configUSE_PREEMPTION != 0 )\r
- {\r
- /* A context switch is only automatically \r
- performed from the tick interrupt if the \r
- pre-emptive scheduler is being used. */\r
- lSwitchRequired = pdTRUE;\r
- }\r
- #endif\r
- \r
- /* Clear the interrupt pending bit. */\r
- ulPendingInterrupts &= ~( 1UL << portINTERRUPT_TICK );\r
- SetEvent( pvTickAcknowledgeEvent );\r
- break;\r
-\r
- case portINTERRUPT_DELETE_THREAD:\r
-\r
- lCurrentTaskBeingDeleted = pdTRUE;\r
-\r
- /* Clear the interrupt pending bit. */\r
- ulPendingInterrupts &= ~( 1UL << portINTERRUPT_DELETE_THREAD );\r
- break;\r
-\r
- default:\r
-\r
- /* Is a handler installed? */\r
- if( vIsrHandler[ i ] != NULL )\r
- {\r
- lSwitchRequired = pdTRUE;\r
-\r
- /* Run the actual handler. */\r
- vIsrHandler[ i ]();\r
-\r
- /* Clear the interrupt pending bit. */\r
- ulPendingInterrupts &= ~( 1UL << i );\r
-\r
- /* TODO: Need to have some sort of handshake \r
- event here for non-tick and none yield \r
- interrupts. */\r
- }\r
- break;\r
+ /* Run the actual handler. */\r
+ if( ulIsrHandler[ i ]() != pdFALSE )\r
+ {\r
+ ulSwitchRequired |= ( 1 << i );\r
+ }\r
}\r
+\r
+ /* Clear the interrupt pending bit. */\r
+ ulPendingInterrupts &= ~( 1UL << i );\r
}\r
}\r
\r
- if( ( lSwitchRequired != pdFALSE ) || ( lCurrentTaskBeingDeleted != pdFALSE ) )\r
+ if( ulSwitchRequired != pdFALSE )\r
{\r
void *pvOldCurrentTCB;\r
\r
/* Suspend the old thread. */\r
pxThreadState = ( xThreadState *) *( ( unsigned long * ) pvOldCurrentTCB );\r
\r
- if( lCurrentTaskBeingDeleted != pdFALSE )\r
+ if( ( ulSwitchRequired & ( 1 << portINTERRUPT_DELETE_THREAD ) ) != pdFALSE )\r
{\r
TerminateThread( pxThreadState->pvThread, 0 );\r
}\r
{\r
/* The task is deleting itself, and so the thread that is running now\r
is also to be deleted. This has to be deferred until this thread is\r
- no longer running, so its done in the pseudo interrupt handler thread. */\r
- vPortGeneratePseudoInterrupt( portINTERRUPT_DELETE_THREAD );\r
+ no longer running, so its done in the simulated interrupt handler thread. */\r
+ vPortGenerateSimulatedInterrupt( portINTERRUPT_DELETE_THREAD );\r
}\r
else\r
{\r
}\r
/*-----------------------------------------------------------*/\r
\r
-void vPortGeneratePseudoInterrupt( unsigned long ulInterruptNumber )\r
+void vPortGenerateSimulatedInterrupt( unsigned long ulInterruptNumber )\r
{\r
xThreadState *pxThreadState;\r
\r
WaitForSingleObject( pvInterruptEventMutex, INFINITE );\r
ulPendingInterrupts |= ( 1 << ulInterruptNumber );\r
\r
- /* The pseudo interrupt is now held pending, but don't actually process it\r
+ /* The simulated interrupt is now held pending, but don't actually process it\r
yet if this call is within a critical section. It is possible for this to\r
be in a critical section as calls to wait for mutexes are accumulative. */\r
if( ulCriticalNesting == 0 )\r
}\r
/*-----------------------------------------------------------*/\r
\r
-void vPortSetInterruptHandler( unsigned long ulInterruptNumber, void (*pvHandler)( void ) )\r
+void vPortSetInterruptHandler( unsigned long ulInterruptNumber, unsigned long (*pvHandler)( void ) )\r
{\r
if( ulInterruptNumber < portMAX_INTERRUPTS )\r
{\r
if( pvInterruptEventMutex != NULL )\r
{\r
WaitForSingleObject( pvInterruptEventMutex, INFINITE );\r
- vIsrHandler[ ulInterruptNumber ] = pvHandler;\r
+ ulIsrHandler[ ulInterruptNumber ] = pvHandler;\r
ReleaseMutex( pvInterruptEventMutex );\r
}\r
else\r
{\r
- vIsrHandler[ ulInterruptNumber ] = pvHandler;\r
+ ulIsrHandler[ ulInterruptNumber ] = pvHandler;\r
}\r
}\r
}\r
if( xTaskGetSchedulerState() != taskSCHEDULER_NOT_STARTED )\r
{\r
/* The interrupt event mutex is held for the entire critical section,\r
- effectively disabling (pseudo) interrupts. */\r
+ effectively disabling (simulated) interrupts. */\r
WaitForSingleObject( pvInterruptEventMutex, INFINITE );\r
ulCriticalNesting++;\r
}\r
ulCriticalNesting--;\r
\r
/* Were any interrupts set to pending while interrupts were \r
- (pseudo) disabled? */\r
+ (simulated) disabled? */\r
if( ulPendingInterrupts != 0UL )\r
{\r
SetEvent( pvInterruptEvent );\r